There are a lot of articles out there claiming Meghan revealed her pet name for Prince Harry when photos were being taken with the cast of Hamilton. Some of the articles claim she turned to Harry and asked, "Can you see, my love?" But that's not a pet name though. According to her former agent, Meghan supposedly calls Harry, 'Haz' for short. And he calls her 'Meg' or 'Megs.' Both are obvious diminutives, and 'my love,' is a figure of speech.
https://www.hellomagazine.com/royalty/2018083161771/meghan-markle-prince-harry-pet-name-royal-news/
The video attached to some of the articles simply shows Meghan looking back at Harry, but we can't hear what she says. Then she seems to look surprised, and covers her mouth. I think these stories are made-up. We do not know why she seemed to say 'Oops' and covered her mouth. She may have taken a mis-step as she was trying to move around and make sure she wasn't blocking Harry in the photo.
One thing I've noticed is how Harry allows Meghan to walk ahead of him, especially on certain occasions, such as the Mandela exhibit, and this Hamilton event. It's as if Harry gives Meghan preference for events that are particularly connected to interests she has, such as 'racial' equality (i.e., Mandela exhibit), and acting (i.e., Hamilton gala). But generally, Harry has always seemed to want Meghan to walk by his side, or in front of him actually, often letting her enter a doorway first. They both seem to be conscious of treating each other as equals. That does go against old-fashioned/ ancient royal protocol. They've always thrown self-conscious stiffness to the wind, with their frequent PDAs that we've seen throughout their relationship. They both have an up-to-date vibe and a compassion for people generally and for young people in particular.
I expect that the Hamilton gala raised a great deal of money for Sentebale, and that's wonderful! I hope we will eventually get to see M&H together touring Sentebale in Botswana.
ETA:
I see someone already posted a link to the Cosmopolitan article, where the 'my love' story originated. We can't hear what Meghan says in the video. And from looking at it, I doubt her reaction had anything to do with embarrassment for what she said to Harry. More likely the photo was being snapped as she turned around, and perhaps that's why she covered her mouth and laughed. We'd have to have been there standing next to her to know for sure what she said.
You most definitely can hear Meghan say " Can you see, my love?" in some of the videos try listening to that part with headphones. After she says it the entire cast said "awww" and at that moment you can see Meghan say "Oh!" because she just realized the cast heard her call Harry my love in public.
It was a sweet moment.